Key Points
- Clostridioides difficile infection (CDI) is among the most prevalent and important healthcare-associated infections (HAIs) affecting children, but reports of CDI in infants <12 months of age are rare, perhaps because of a relative resistance to the effects of C. difficile toxins or other protective factors in the intestinal environment of infants.
- Additionally, high colonization rates in infants (~35%) make interpretation of positive C. difficile tests in neonatal intensive care units (NICU) patients uniquely challenging.
- For these reasons, the authors do not recommend routine testing for C. difficile in NICU patients.
- NICU patients should be evaluated for other more common causes of diarrhea.
Diagnosis
Testing for CDI
- The authors advise against routine testing for CDI in NICU patients because of the high prevalence of asymptomatic carriage of toxigenic C. difficile in infants <12 months of age. When C. difficile or its toxins are detected in the stool of an infant, clinicians may not be able to determine with certainty that a positive result represents CDI.
- Clinicians should test NICU patients for CDI only if there is evidence of pseudomembranous colitis or if the patient has clinically significant diarrhea and other noninfectious and infectious causes of diarrhea have been excluded.
- Before testing a NICU patient with suspected infectious diarrhea for CDI, clinicians should:
- Perform a thorough investigation for potential noninfectious causes of diarrhea in NICU patients.
- Test the stool for norovirus, rotavirus, adenovirus, and enterovirus.
- Consider bacterial stool cultures (e.g., Salmonella, Shigella, Campylobacter, Yersinia, and Shiga-toxin–producing E. coli) for infants who were admitted to the NICU from the community, or who have a known or suspected exposure to bacterial enteritis.
- If clinicians consider testing a NICU patient for CDI, the authors advise using a stool toxin test as part of a multistep algorithm rather than using a nucleic acid amplification test (NAAT) alone.
- The facility should not use toxin enzyme immunoassay (EIA) as a stand-alone test to diagnose CDI.
- Repeat testing after a negative result and tests of cure are not recommended.
- Because CDI is a toxin-mediated disease, any testing strategy must include detection of either toxin or a toxigenic organism.
- 1. NAATs, primarily polymerase chain reaction testing for the genes for toxins A and B,
- are more sensitive for C. difficile detection than toxin EIA tests, but
- their positive predictive value can be low, particularly when the prevalence of colonization is high (as is true for infants).
- 2. Toxin EIA testing:
- in addition to having lower sensitivity than NAAT, may also be prone to false-positive results in children.
- is not recommended as a stand-alone approach to diagnosis.
- 3. Glutamate dehydrogenase (GDH) immunoassays:
- detect a highly conserved antigen present in all C. difficile isolates.
- can be used as a component of 2- or 3-step algorithms with subsequent toxin testing, in which a negative toxin EIA result is sometimes arbitrated by NAAT as outlined in the IDSA/SHEA guideline.
- 1. NAATs, primarily polymerase chain reaction testing for the genes for toxins A and B,
